Kohler toilet seat replacement for one-piece.

I have a one piece kohler toilet and am trying to replace the seat. the problem is that one of the anchor screws will not come out of the toilet. I keep turning it (unscrewing it) but it appear to be stuck. how do I get it out? any suggestions? i've looked at the kohler site but have not foun any useful information.
i'm thinking of cutting the screw in order to pull it out.

As of today, I am having the same issue.
I think there is some sort of an anchor system used on our toilets.
Here is my story -
My seat has never been snug since I'd bought my house. After having enough of it, I popped the caps on the back of the seat and took a flat-head screwdriver to them..... They just spun w/ no backing out and no tightening up.
There is no way to get to the back side of our seat mounts. No nut under the tank, inside the tank- Its all contained.
FINALLY I just broke the seat off the commode, and pried the anchor-type securement out of the holes. It appears that the previous owner over-tightened them and snapped it.
I took it to Lowes and they were no help. They told me to visit a specialty tool supply store.
I've done all I can do to find a part number or a diagram online....
I'm at a loss as well.
Expensive toilet..... no parts..... Great.....

on my one piece units (san raphael and rochelle) the nut for the seat bolt is reachable from the tank. i would not buy a replacement seat from kohler, as it will run as much as a new toilet. there are aftermarket products, but watch the color ... there's a kohler color table at this link

a company called church makes some replacements or you can google "kohler toilet seat" and find several manufacturers. and there's always ****. with shipping you can get one for less than $40. i bought one for less than $20 new in the box, but alas, the blue was not HERON BLUE that matches my 20 year old units. good luck.

I am trying to change a toilet seat. This is a Kohler one piecce toilet over 10 years old. inside the lid are the following numbers: T 54, K45E0 (the E looks like a backward 3) 21820, 2 2087.
the old seat was screwed into what looks like a nut, which is now rotating with every turn I make, thus I am making no progress. Also, the screw is much smaller in diameter than the hole. Once I get the seat off I don't see how I will get to replace it...

I have a similar problem, the seat anchors are broken and kohler does not provide replacement anchors with the seat that they recommend for the model toilet.
I contacted kohler through the website e-mail address and they wanted $47 for the 2 anchors and a special tool to remove the old anchors. I replied that I did not need the $46 tool, just the $1 anchors. Their response was to offer a small discount.
Desperate to attach the seat, I inserted a large plastic anchor and, although loose, the seat is attached.
I have since found a manufacturer, Bemis, who apparently sells a kit to attach their seat to the Kohler one-piece. I've not contacted them yet, but I'll post if I'm successful.
What really bother's me about Kohler, is that at the same time I bought the toilets, I replaced the faucets with Moen products, which come with a lifetime guarantee. After a few years, the white coating on the faucets chipped and Moen replaced both faucets at no charge. I suppose Kohler is comfortable enough with their position in the market to not care about repeat business.
Good luck.

I will see if I can figure out a way to phtograph it that will have meaning. The top is just the two holes. There is no other way that I can figure out to access the area I would expect to attach the nuts.

The rest of the outside is just the toilet exterior. Inside the tank the area where the nuts might go is just closed off. There is no exterior access either.

So either they have some magical way of mounting it that isn't for sale at Home Depot, (even when you buy a Kohler seat), or I will just have to live without a seat on this toilet until I replace it. We have other toilets. But it is a bit inconvenient.

I found this posting concerning the same issue.How to repair/replace a Kohler seat that has the anchor bolts

If you have a Kohler toilet that requires the Kohler seat anchor kit 84999, here is an inexpensive alternative
Step 1

If you have one of the Kohlers with the Kohler anchor bolts holding the seat, do not buy the $46 anchor bolt kit 84999.

Step 2

Instead, remove the old anchors and bolts which have an aluminum end which the stainless bolt screws into and over time become corroded together. Use a 1/8" drill and drill around the bolt removing the anchor material until the bolt can be pulled out.

Step 3

Carefully clean the hole with a 11/32" drill to remove all the remaining anchor material.

Step 4

Then go to your local hardware store and buy a 10-32 3/8"x3/4" rubber expansion plug (check to be certain the threaded part is brass and it has a shoulder on one end), a 10-32x1.5" Phillips bolt and a couple of small fender washers to fit the seat. Total cost under $4.00 for two.
5.
Step 5

Assemble being careful to not tighten too much and crack the porcelain.

Of course, I found out, trying to find 10-32 3/8"x3/4" rubber expansion plugs is not that easy. They didn't have them at HD (or at least no one knew where they were if they did). I went to True Value Hardware and they had every size but.

I tried a size larger and they wouldn't fit in the holes. So now I go on the great rubber expansion plug safari.

I had the same problem. I took the existing screws out that were stripped. You may have to cut the heads of the screws off with a hacksaw. Make sure you leave enough of the screw so you can grab it with a plier and remove it. The only thing that worked for me was 3" plastic wall plug. I think thats what it is called. You put into a sheet rock wall and screw in a screw and it expands so you can mount things on the wall. I tapped the plastic plug into the two holes in the toliet where the seat mounts. I then placed the toliet seat on top of holes and screwed in the mounting screws. The plastic wall plugs expand securing the toliet seat. So far the seat does not move. We will see after several more uses.